Deep tillage and residue mulch effects on productivity and water and nitrogen economy of spring maize in north-west India

摘要

Alarming decline of groundwater levels in last two decades in Punjab state of north-west India has limited the scope of high water-requiring, but otherwise profitable spring maize crop. This water limitation also calls for optimizing use of fertilizer nitrogen (N). Interventions like tillage and residue management help to address these constraints. This study examined the effects of deep tillage, irrigation, residue mulch and N regimes on root growth, water use, N uptake and productivity of spring maize in a sub-tropical environment. Combinations of two tillage systems viz., deep tillage (DT) and conventional tillage (CT), with two irrigation regimes viz., irrigation water to pan evaporation ratio of 1.0 (I-1.0) and 0.5 (I-0.5) in main plots; and combinations of four N rates viz., 0 (N-0), 50 (N-1), 100 (N-2) and 150 (N-3) kg ha(-1) with two mulch rates viz., 0 (M-0) and 6 t ha(-1) (M) in subplots were randomized with three replications.